Geant4 simulation of detection efficiency and self-attenuation effect of β particles for radioxenon measurement using β-γ coincidence equipment

Measurement of radioxenon isotopes is one of the key components of the verification regime of the comprehensive nuclear-test-ban treaty. The beta-gamma coincidence technique is the most sensitive method for radioxenon isotopes detection. The self-attenuation effect of beta-particles is unavoidable during beta-gamma coincidence measurement due to the presence of gas matrixes, such as stable xenon and other carrier gases, in the sample. In this study, the detection efficiencies of beta-particles for radioxenon isotopes in different volumes of different gas matrixes (xenon, nitrogen, and helium) were simulated using Geant4 and the self-attenuation effects were deduced accordingly. The method to correct for the self-attenuation effects was thereby provided.

Automated summary

The measurement of radioxenon isotopes is crucial for the verification of the comprehensive nuclear-test-ban treaty, with the beta-gamma coincidence technique being the most sensitive method. However, the self-attenuation effect of beta-particles is a challenge when gas matrixes are present in the sample. This study simulated the detection efficiencies of beta-particles for radioxenon isotopes in different gas matrixes and provided a method to correct for the self-attenuation effects.